The Excel Odd function rounds a supplied number away from zero (ie. rounds a positive number up and a negative number down), to the next odd number.
The syntax of the function is:
Where the number argument is the numeric value that you want to round. This can be supplied directly to the function, or it can be provided as a reference to a cell containing a number, or a value returned from another function or formula.
The following spreadsheets show the Excel Odd function used to round several different numbers. The formulas are shown in the spreadsheet on the left and the results are shown in the spreadsheet on the right:
Formulas:

Results:

The above examples show how the odd function always rounds away from zero, to the next odd number.  ie. If the supplied number is positive, it is rounded up (more positive), but if the supplied number is negative, it is rounded down (less negative).
If the number argument is exactly equal to zero, as shown in cell B4 of the example spreadsheet above, the Excel Odd function rounds to the positive value +1.
For further examples of the Excel Odd Function, see the Microsoft Office website.